Microbiology of antimicrobial resistance

In this video, Dr Diaa Alrhamany provides a quick overview of the types of resistance, the mechanisms of resistance and briefly mentions the importance of surveillance which will be discussed further in week two of the course.

We can broadly define bacterial resistance in two categories:

• Microbiological resistance
  • This is achieved through the adaptation of specific biological mechanisms that may render them less susceptible or even absolutely resistant to antimicrobials.
• Clinical resistance
  • This is when the bacteria is exposed to properly-selected antibiotics, administered in adequate dose for the necessary duration with unmet clinical outcomes.

Types of resistance:

• Down-regulation of the cell porins, which serves as the entrance passage for the antibiotics

• Minimising the availability of antibiotics intracellularly through over-expression of the efflux pumps

• Deactivating enzymes by altering the target

• They can also hide from the action of antibiotics through the biofilm construction

Resistance may be due to a single mechanism or multiple mechanisms. Enzymatic deactivation of the antimicrobials remains the most common and effective resistance tool of the bacteria.

Data must be expressed in a way that can be used by the practitioners in their daily clinical practice through surveillance studies such as antibiograms. This will be discussed further in step 2.5. Furthermore, this data can then be used for the research and development of antimicrobials to provide alternative or novel medications for the treatment of these resistant infections.

The next step will discuss what AMS is and why it is important.